One-to-One / Group Chat

Build a focused one-to-one or group chat experience in iOS with CometChat UI Kit.

AI Integration Quick Reference

Field	Value
Package	CometChatUIKitSwift
Framework	UIKit / SwiftUI
Components	CometChatMessageHeader, CometChatMessageList, CometChatMessageComposer
Layout	Single chat window — no sidebar, no conversation list
Prerequisite	Complete iOS Integration Steps 1–4 first
Pattern	Support chat, embedded widgets, focused messaging

This guide builds a single chat window — no sidebar, no conversation list. Users go directly into a one-to-one or group chat. Good for support chat, contextual messaging, or any focused messaging experience.

This assumes you’ve already completed iOS Integration (project created, UI Kit installed, init + login working, permissions configured).

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What You’re Building

Three components stacked vertically:

1. Chat header — displays recipient name, avatar, online status, and optional call buttons
2. Message list — real-time chat history with scrolling
3. Message composer — text input with media, emojis, and reactions

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Step 1 — Setup SceneDelegate

Fetch the user (or group) after login and launch directly into the messages view.

SceneDelegate.swift

import UIKit
import CometChatUIKitSwift
import CometChatSDK

class SceneDelegate: UIResponder, UIWindowSceneDelegate {

    var window: UIWindow?

    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        guard let windowScene = (scene as? UIWindowScene) else { return }

        let uikitSettings = UIKitSettings()
            .set(appID: "APP_ID")        // Replace with your App ID
            .set(region: "REGION")       // Replace with your Region
            .set(authKey: "AUTH_KEY")    // Replace with your Auth Key (dev only)
            .subscribePresenceForAllUsers()
            .build()

        CometChatUIKit.init(uiKitSettings: uikitSettings) { result in
            switch result {
            case .success:
                debugPrint("CometChat initialized")

                let uid = "cometchat-uid-1"

                CometChatUIKit.login(uid: uid) { loginResult in
                    switch loginResult {
                    case .success:
                        debugPrint("Login successful")

                        DispatchQueue.main.async { [weak self] in
                            self?.setUpOneOneOrGroupConversation(
                                windowScene: windowScene,
                                uid: "cometchat-uid-2"  // The user to chat with
                            )
                        }

                    case .onError(let error):
                        debugPrint("Login failed: \(error.description)")
                    @unknown default: break
                    }
                }

            case .failure(let error):
                debugPrint("Init failed: \(error.localizedDescription)")
            }
        }
    }

    func setUpOneOneOrGroupConversation(windowScene: UIWindowScene, uid: String) {
        CometChat.getUser(UID: uid) { user in
            DispatchQueue.main.async {
                let messagesVC = MessagesVC()
                messagesVC.user = user
                
                let navController = UINavigationController(rootViewController: messagesVC)
                self.window = UIWindow(windowScene: windowScene)
                self.window?.rootViewController = navController
                self.window?.makeKeyAndVisible()
            }
        } onError: { error in
            debugPrint("Failed to fetch user: \(error?.description ?? "")")
        }
    }
}

Key points:

• CometChat.getUser(UID:) fetches the user object from the SDK — you need a real user object, not a manually constructed one.
• The highlighted lines show where to set the credentials and the UID of the user to chat with.

---

Switching Between User and Group Chat

To load a group chat instead of one-to-one, replace getUser with getGroup:

func setUpGroupConversation(windowScene: UIWindowScene, guid: String) {
    CometChat.getGroup(GUID: guid) { group in
        DispatchQueue.main.async {
            let messagesVC = MessagesVC()
            messagesVC.group = group
            
            let navController = UINavigationController(rootViewController: messagesVC)
            self.window = UIWindow(windowScene: windowScene)
            self.window?.rootViewController = navController
            self.window?.makeKeyAndVisible()
        }
    } onError: { error in
        debugPrint("Failed to fetch group: \(error?.description ?? "")")
    }
}

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Step 2 — Create MessagesVC

Create a new Swift file for the messages view controller:

1. In Xcode, right-click your project folder in the Navigator
2. Select New File…
3. Choose Swift File and click Next
4. Name it MessagesVC.swift and click Create

Add the following code. This view controller assembles the header, message list, and composer.

MessagesVC.swift

import UIKit
import CometChatSDK
import CometChatUIKitSwift

class MessagesVC: UIViewController {
    
    // MARK: - Properties
    var user: User?
    var group: Group?
    
    // MARK: - UI Components
    private lazy var headerView: CometChatMessageHeader = {
        let view = CometChatMessageHeader()
        view.translatesAutoresizingMaskIntoConstraints = false
        if let user = user {
            view.set(user: user)
        } else if let group = group {
            view.set(group: group)
        }
        view.set(controller: self)
        return view
    }()
    
    private lazy var messageListView: CometChatMessageList = {
        let listView = CometChatMessageList()
        listView.translatesAutoresizingMaskIntoConstraints = false
        if let user = user {
            listView.set(user: user)
        } else if let group = group {
            listView.set(group: group)
        }
        listView.set(controller: self)
        return listView
    }()
    
    private lazy var composerView: CometChatMessageComposer = {
        let composer = CometChatMessageComposer()
        composer.translatesAutoresizingMaskIntoConstraints = false
        if let user = user {
            composer.set(user: user)
        } else if let group = group {
            composer.set(group: group)
        }
        composer.set(controller: self)
        return composer
    }()
    
    // MARK: - Lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()
        configureView()
        setupLayout()
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        navigationController?.setNavigationBarHidden(false, animated: true)
    }
    
    // MARK: - Setup
    private func configureView() {
        view.backgroundColor = .systemBackground
        navigationController?.setNavigationBarHidden(true, animated: false)
    }
    
    private func setupLayout() {
        [headerView, messageListView, composerView].forEach { view.addSubview($0) }
        
        NSLayoutConstraint.activate([
            // Header
            headerView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            headerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            headerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            headerView.heightAnchor.constraint(equalToConstant: 50),
            
            // Message list
            messageListView.topAnchor.constraint(equalTo: headerView.bottomAnchor),
            messageListView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            messageListView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            messageListView.bottomAnchor.constraint(equalTo: composerView.topAnchor),
            
            // Composer
            composerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            composerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            composerView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
        ])
    }
}

How it works:

• CometChatMessageHeader shows user/group info and back button
• CometChatMessageList displays messages with real-time updates
• CometChatMessageComposer handles text input, media, and reactions
• Pass either user or group to each component, never both

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Step 3 — Run the Project

Build and run in Xcode. You should see the chat window load directly with the conversation for the UID you set.

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Next Steps

Theming

Customize colors, fonts, and styles to match your brand

Components Overview

Browse all prebuilt UI components

iOS Integration

Back to the main setup guide

Core Features

Chat features included out of the box